Gems to make military eyes sparkle

As Marilyn Monroe sang in the 1953 classic film Gentlemen Prefer Blondes, diamonds are a girl's best friend.

That still stands for many today and not only girls. The hard-nosed top brass of the US military may be about as far from Monroe as one could imagine but they share a love of sparklers.

And big guns in the defence industry are the purveyor of their dreams.

One such is Raytheon, a giant with sales last year of US$24 billion (Dh88.14bn) and 68,000 employees worldwide.

The company is exploring the potential of the gem for military use and, rather than costing a fortune, its diamonds could well save one.

By incorporating the stones into cutting-edge semiconductor components, the company is aiming to revolutionise areas such as radar, and electronic warfare and communications systems.

"It enables more reliable systems with less weight and space, which translates into fuel savings and lower maintenance costs - saving money over the life of the system," says Raytheon's integrated defence systems advanced technology programs technical director Colin Whelan on the company website.

However, these stones are not dug out of the ground.

The "mines" in this case are operated by earnest boffins in spotless lab coats.

Laboratory-grown diamonds, when combined with the semiconductor gallium nitride, could be an essential element for the next generation of radar, communications and electronic warfare systems.

According to Professor Sir Colin Humphreys of the department of materials science and metallurgy at the University of Cambridge in the United Kingdom, gallium nitride is probably the most important semiconductor material since silicon.

"It can be used to emit brilliant light in the form of light emitting diodes [LEDs] and laser diodes, as well as being the key material for next generation high frequency, high power transistors capable of operating at high temperatures," he says on the department's website.

The Cambridge centre for gallium Nitride is based at the University of Cambridge.

"We are one of a small number of places in the world to have, in close proximity and on the same site, gallium nitride growth equipment," says Prof Humphreys.

The Integrated Air Defence Centre is home to some of Raytheon's most successful projects, including the Patriot missile system.

Just 30km outside Boston, it is also where Raytheon "mines" diamonds.

Monroe would be disappointed to find the facility would not grow her a whopper.

"I've had several guys who are getting engaged say, 'Hey, can you grow me a diamond for my ring?'" says Ralph Korenstein, who runs Raytheon's diamond laboratory.

"I have people try to put in orders with me," he says.

"But we're not in the jewellery business.

"But diamonds aren't just pretty," he adds. "They have a practical use. You can see farther, you can get more power."

In the early days of development, Raytheon used a standard microwave to research artificial diamond technology.

"They used to sell that [model of oven] to cook hot dogs or whatever," Mr Korenstein says.

To create its diamonds today, Raytheon uses an industrial microwave reactor.

Engineers first dose the reactors, which are filled with hydrogen and methane, with microwaves.

The gases are superheated and diamond crystals begin to form from the carbon in the methane, which collect on a metal plate and over time, it forms a disc of the super-hard material.

To accelerate the growth process, scientists spray the metal plate with diamond "seeds".

To grow a disc of high-quality diamond about 12cm wide takes about a month - somewhat faster than the millions of years the process takes naturally.

Raytheon's diamond plates are grown in a range of sizes and workers polish the discs - perhaps ironically - by using more diamonds. The final step is to use lasers to cut the diamonds into the required shapes.

In April of last year, the US defence advanced research projects agency, which commissions advanced research for the department of defence, awarded Raytheon an 18-month, $1.8 million contract to develop the next-generation semiconductor component thermally enhanced gallium nitride bonded to diamond layers.

Gallium nitride components can emit five times the radio energy of the conventional gallium arsenide technology in use today. Raytheon hopes developing this technology will enable it to produce more affordable, smaller, lighter and more powerful and efficient systems for radar, signal jammers, electronic warfare and communications.

Diamond is an excellent "heat sink" and it is this quality that is particularly attractive - to the squared-jawed brass hats of US defence at least.

Gallium nitride components create a huge amount of heat that needs to be conducted safely away from delicate and sophisticated electronic systems, and this is why Raytheon's new generation of gallium nitride devices is bonded to diamonds.

"Whenever the juncture temperature is still too high, it's vital to locate a better heat-spreader material," says Linda Wagner, a senior director of Raytheon's radio frequency components business.

"Diamond is perfect for this as a replacement for a more conventional heat spreader."

Raytheon's diamonds have already entered the electronics market and have been used in instruments for the Spirit and Opportunity rovers used by Nasa as part of its Mars exploration programme. Both vehicles were designed for a 90-day mission in 2004.

Spirit finally gave up the ghost in 2010 and Opportunity is still operating - a testament to the quality of the design and components used.

In an era of fiscal austerity and looming defence cuts in the United States, diamond-enabled technology can be used to create higher performance identification and attack systems in current military planes and ships.

And that is far cheaper and faster than redesigning and building a new generation of military hardware to take new technology.

"Pockets aren't as deep as they once were," says Joseph Biondi, the vice president of advanced technology programmes at Raytheon.

"This technology enables us to keep bringing high-performance solutions to our customers who need it, but within a price range that they can live with."

business@thenational.ae